A rich source of anticancer compound ajoene, antioxidants, antimicrobials and a very safe biopesticide.
Garlic (Allium sativum), our common spice, is rich in protein (6%) and carbohydrates (29%) and contain appreciable amounts of copper.
The bulbs yield 0.06-0.1% essential oil containing allyl propyl disulphide and diallyl sulphide.
The antiseptic principle of garlic is a sulphoxide, allicin, which on distillation is converted to diallyl sulphide, diallyl trisulphide, and allyl propyl disulphide.
Garlic contains 13 antibacterial compounds.
The medicinal properties of Garlic are as follows.
1. Anticancer compound
“Ajoene”, formed in garlic preparations, is an efficient anti-leukaemia agent for acute myeloid leukaemia.
It is shown effective in inhibiting tumour cell growth by targeting the microtubule cytoskeleton of such cells and by other mechanisms.
Ajoene decreases basal cell carcinoma tumor size by inducing apoptosis- a process where a cell is degraded in order for it to be ultimately engulfed and recycled.
Ajoene, (4,5,9-trithiadodeca-1,6,11-triene-9-oxide) is an unsaturated disulphide, is formed when allicin is dissolved in various solvents including edible oils or acetone.
One molecule of ajoene is formed from two molecules of allicin.
Allicin is not present in intact garlic bulbs but is formed by the action of the enzyme allinase on alliin at the time of crushing or chopping.
Allicin is a sulfinyl compound that gives garlic its strong odour and flavor.
Ajoene is also found in garlic extract.
Ajoene is most stable and most abundant in macerate of garlic (chopped garlic in edible oil).
2. Garlic is rich in antioxidants.
The main antioxidant compounds in garlic are allyl disulfide, alliin, allicin, and allyl cysteine and they exhibit different patterns of antioxidant activities as protective compounds against free radical damage.
Both alliin and allyl cysteine were hydroxyl scavengers, and allyl disulfide was a lipid peroxidation terminator.
Allicin is found to increase the blood levels of two antioxidant enzymes – catalase and glutathione peroxidase.
Allicin acts as an effective antioxidant against the oxidative damage caused by nicotine and protects vascular endothelial cells from oxidant injury.
It also prevents the oxidation of LDL cholesterol and inhibits lipid peroxidation in the liver, which slows down the ageing process in liver cells.
3. Garlic is used to help prevent heart disease, including atherosclerosis or hardening of the arteries.
It is found that allicin blocks the enzymes responsible by reacting with one of their important reactive groups known as sulfhydryl (SH) groups, or thiols.
This finding has important implications because sulfhydryl groups are also crucial components of some enzymes that participate in the synthesis of cholesterol.
By reacting with and modifying the sulfhydryl groups in those enzymes, allicin may prevent the production of artery clogging cholesterol.
4. Garlic is believed to boost the immune system.
Allicin is found to inhibit the SDF-1α (CXCL12)-induced T cell migration through fibronectin (FN), and that this inhibition is mediated by the down-regulation of (i) the reorganization of cortical actin and the subsequent T cell polarization, and (ii) T cell adhesion to FN. Moreover, allicin also inhibited T cell adhesion to endothelial cells and transendothelial migration.
The ability of allicin to down-regulate these chemokine-induced and VLA-4-mediated T cell functions explains its beneficial biological effects in processes where T cells play an important role and suggests that allicin may be used therapeutically with chronic inflammatory diseases (Sela et al., 2004).
Other medicinal properties of Ajoene include blood thinning and antimicrobial.
Garlic is one of the best Biopesticide also.
used against aphids, army worms, colarado beetle, kharpa beetle, codling moth, cabbage worm, wire worms.
Garlic in kerosene / mineral oil / soap is used against American bollworm, onion thrips, root knot nematode, potato tuber moth, sugar cane shoot borer/ bacterial diseases, anthracnose, downy mildew, rice blast etc.
Garlic extracts are found effective against a number of plant parasitic nematodes such as Meloidogyne incognita, M. javanica, Radopholus similis, Aphelenchoides sacchari and Tylenchulus semipenetrans.
Source: M.Daniel (2012) “Useful Herbs of Planet Earth” (Scientific Publishers, Jodhpur/ New Delhi, pp 378- 419.
Mammen Daniel
